---
title: Containerize a Python application
linkTitle: Containerize your app
weight: 10
keywords: python, flask, containerize, initialize
description: Learn how to containerize a Python application.
aliases:
  - /language/python/build-images/
  - /language/python/run-containers/
  - /language/python/containerize/
  - /guides/language/python/containerize/
---

## Prerequisites

- You have installed the latest version of [Docker Desktop](/get-started/get-docker.md).
- You have a [git client](https://git-scm.com/downloads). The examples in this section use a command-line based git client, but you can use any client.

## Overview

This section walks you through containerizing and running a Python application.

## Get the sample application

The sample application uses the popular [FastAPI](https://fastapi.tiangolo.com) framework.

Clone the sample application to use with this guide. Open a terminal, change directory to a directory that you want to work in, and run the following command to clone the repository:

```console
$ git clone https://github.com/estebanx64/python-docker-example && cd python-docker-example
```

## Initialize Docker assets

Now that you have an application, you can create the necessary Docker assets to
containerize your application. You can use Docker Desktop's built-in Docker Init
feature to help streamline the process, or you can manually create the assets.

{{< tabs >}}
{{< tab name="Use Docker Init" >}}

Inside the `python-docker-example` directory, run the `docker init` command. `docker
init` provides some default configuration, but you'll need to answer a few
questions about your application. For example, this application uses FastAPI to
run. Refer to the following example to answer the prompts from `docker init` and
use the same answers for your prompts.

```console
$ docker init
Welcome to the Docker Init CLI!

This utility will walk you through creating the following files with sensible defaults for your project:
  - .dockerignore
  - Dockerfile
  - compose.yaml
  - README.Docker.md

Let's get started!

? What application platform does your project use? Python
? What version of Python do you want to use? 3.11.4
? What port do you want your app to listen on? 8000
? What is the command to run your app? python3 -m uvicorn app:app --host=0.0.0.0 --port=8000
```

Create a file named `.gitignore` with the following contents.

```text {collapse=true,title=".gitignore"}
# Byte-compiled / optimized / DLL files
__pycache__/
*.py[cod]
*$py.class

# C extensions
*.so

# Distribution / packaging
.Python
build/
develop-eggs/
dist/
downloads/
eggs/
.eggs/
lib/
lib64/
parts/
sdist/
var/
wheels/
share/python-wheels/
*.egg-info/
.installed.cfg
*.egg
MANIFEST

# Unit test / coverage reports
htmlcov/
.tox/
.nox/
.coverage
.coverage.*
.cache
nosetests.xml
coverage.xml
*.cover
*.py,cover
.hypothesis/
.pytest_cache/
cover/

# PEP 582; used by e.g. github.com/David-OConnor/pyflow and github.com/pdm-project/pdm
__pypackages__/

# Environments
.env
.venv
env/
venv/
ENV/
env.bak/
venv.bak/
```

{{< /tab >}}
{{< tab name="Manually create assets" >}}

If you don't have Docker Desktop installed or prefer creating the assets
manually, you can create the following files in your project directory.

Create a file named `Dockerfile` with the following contents.

```dockerfile {collapse=true,title=Dockerfile}
# syntax=docker/dockerfile:1

# Comments are provided throughout this file to help you get started.
# If you need more help, visit the Dockerfile reference guide at
# https://docs.docker.com/go/dockerfile-reference/

# Want to help us make this template better? Share your feedback here: https://forms.gle/ybq9Krt8jtBL3iCk7

ARG PYTHON_VERSION=3.11.4
FROM python:${PYTHON_VERSION}-slim AS base

# Prevents Python from writing pyc files.
ENV PYTHONDONTWRITEBYTECODE=1

# Keeps Python from buffering stdout and stderr to avoid situations where
# the application crashes without emitting any logs due to buffering.
ENV PYTHONUNBUFFERED=1

WORKDIR /app